Dyes for color photography



United States Patent Cfitice 3,119,811 Patented Jan. 28, 1964 3,119,811 DYES FER QOLUR PHQTGGRAPHY Paul Dreytnss, Basel, Switzerland, assignor to Ciba States Limited, New York, FLY. No Drawing. Filed Sept. 7, 1960, Ser. No. 54,381 Claims priority, application Switzerland Sept. 9, B59 7 Claims. (Cl. 260179) The present invention provides dyes for the silver dye bleach process as well as photographic material containing such dyes for the silver dye bleach process and color photographs produced therefrom.

It is known that it is possible to produce with the aid of the silver dye bleach process, which is based on the removal of dyes corresponding to the image, monochrome or polychrome photographic records. In the silver dye bleach process the image is first formed by a known photographic method by exposure and development as a silver image in a photosensitive layer homogeneously dyed with a dye. The dye present in the layer is then removed in a silver dye bleach bath in each image area proportional to the amount of image silver present in it. The silver is then removed, whereupon a dye image opposite to the original silver image is obtained. As with the known multi-pack materials which are processed according to the color coupling development there is used also in the silver dye bleach process for the production of polychrome photogr'iphs advantageously a multi-layer material comprising in general three separate component dye layers Whose sensitivity is restricted to the associated spectral areas. For example, in a preferably used multilayer combination the base is coated, one upon another, with a first layer sensitized to red containing a bluish green (cyan) dye, a second layer sensitized to green containing a purple (magenta) dye, a third yellow filter layer for eliminating any short-wave rays that are a disturbing factor in view of the inherent sensitivity of tr e two underlying layers, and as the topmost layer a non-sensitized, that is to say blue-sensitive, layer containing a yellow dye.

The dyes used in photographic material to be processed by the silver dye bleach process must satisfy an extremely varied range of requirements. Apart from having to be easy to bleach out, as is needed for the silver dye bleach process, such dyes must be readily soluble in Water; they must not tend to diffuse in gelatine or other film-forming colloids; and they must not have an adverse effect on the photographic eroperties of the silver halide emulsion in which they are incorporated. They must be fast to light and possess pure tints.

in the silver dye bleach process increased photosensitivity in the individual layers is of special importance because the photosensitive silver halide layer contains a dye already at the exposure stage which dye absorbs the available exposure lig it and thereby diminishes the photosensitivity of the layer. The sensitizing of such dyed layers is further rendered very diflicult by the fact that the hitherto known dyes used for sensitizing the layer have a strong desensitizing action on the emulsion over and above the aforementioned action of the absorption which decreases the photosensitivity.

The present invention provides new dyes which are particularly suitable for the aforementioned purpose and correspond to the general formula wherein D and E represent aliphatic radicals which together contain at least 5 carbon atoms; X and Y each represent a hydrogen atom or a monovalent substituent or, when X and Y are vicinal, they may constitute the complement required to form a further ring, and L and M each represent a radical of an aminohydroxynaphthalene-sulfonic acid bound to the azo linkage in vicinal position to the hydroxyl group.

The dyes oi the Formula 1 can be prepared by coupling in a known manner an aminohydroxynaphthalenesultonic acid with a tetrazo compound of a diamine of the formula in which D, E, X and Y have the above meanings.

The diamines of the Formula 2 are likewise available by known methods, by condensing an aromatic amine of the formula 3 X in an acid medium with an aliphatic ketone containing at least 6 carbon atoms.

Particularly suitable amines of the Formula 3 are aminobenzene and aminobenzenes substituted by halogen atoms such as chlorine, by alkyl groups such as methyl or ethyl, or by alkoxy groups such as methoxy or ethoxy, for example l-amino-B-chlorobenzene, 1-amino-2-methylor-2-ethylbenzene, 1-amino-2:5- or -226-dimetl1ylbenzene or 1-amino-2-methoxy-benzene. As an amine of the Formula 3 whose substituents X and Y are vicinal and form the complement to a further ring there may be mentioned l-aminonaphthalene.

The aliphatic ketones to be condensed with such amines contain at least 6 carbon atoms, and, advantageously, in addition to the oxygen atom of the keto group only carbon and hydrogen atoms. They correspond, for example, to the formula and advantageously at least one of them contains more 4 than 5, for example 6 to 20, carbon atoms. Suitable wherein the two Zs have the above meaning; U represents ketones of the Formula 4 are for example a CO- or SO group, and R an unsubstituted or Methy1 n amy1kemne substituted benzene radical. The benzene radical may con- Methy] n hexylketone tam, for example, as further substituent an alkyl group Methypmheptylketone such as methyl or a halogen atom such as chlorine, or Methyl n nonylketone an acetylamlno group, and 1f desired it may contain two or three substituents so that it corresponds, for example,

Ethyl-n-butylketone Diisobutylketone to the formula Di-(n-heptyl)-ketone 1O (3) Y Y While the known condensation products of aromatic -V amines are relatively easy to isolate in the form of crystallines substances with acetone, benzymethylketone or the V V like, condensation products with higher aliphatic ketones in which 2 to 5 Vs represent hydrogen atoms, 0 to 2 Vs have very little crystallization tendency. Accordingly, methyl groups, 0 or 1 V represents a chlorine atom and the condensation products of the Formula 2 must be 0 or 1 V an acetylarnino group.

isolated from the condensation mixtures either by frac- The formulae of the preferred dyes can be worked out tional distillation or preferably by treating the crude conwithout difliculty from the above specifications and fordensation mixture with an acylating agent such, for exmulae of the intermediates. In this connection special ample, as acetic anhydride or nitrobenzoyl chloride, mention is made only of the dyes of the formula Acyl-HN 011 X X no NII-Aeyl whereupon the readily crystallizing acylated derivatives in which D, E, X, Y and Z have the above meanings and 0f the f rm the acyl groups are preferably made up of a CO- or (5) X X S O bridge and a radical of the Formula 8.

The new dyes of the Formula 1 are particularly suitable for incorporation in silver halide emulsions for the production of color photographs by the so-called silver dye Y Y bleach process, because they satisfy extensively the numerous requirements mentioned below which arise in said process, namely:

They must be compatible with the silver halide emulsion, more especially with an optically sensitized silver bleachable without leaving colored radicals. They must be fast to light, more especially in the case of records viewed by incident light, and their absorption must satisfy certain spectral conditions.

In general, these dyes are purple dyes of a particularly pure tint. Insofar as they tend to diifuse they can be made stable to diffusion with basic precipitating agents such, for example, as a biguanide. By suitably selecting the components the degree of diffusion can be varied.

When the radicals D and E in the diamines are increased,

the resulting dyes are more stable to diffusion. However,

the necessary size of D and E depends also on the contribution which the coupling component makes to the diffusion stability; it suffices therefore to use a diamine with relatively small D and E radicals to render the (6) HO I W disazo dye from 2 mols of a coupling component of large molecular size, or one which imparts to the dye afiinity for the base, stable to diffusion.

The dyes, more especially those of the Formula 9 are obtained from which the pure diamines are obtained by hydrolysis, preferably in an acid medium. The acid solutions obtained by hydrolysing the acylated amines can 40 be used as they are for the tetrazotization and dye coupling or, alternatively, the base can first be liberated from the hydrolysis solution.

The aminohydroxynaphthalenesulfonic acids to be coupled with the tetrazo compounds of the diamines of the Formula 2 may contain one or two sulfonic acid groups and a primary or substituted amino group, for example a phenylamino group or preferably an acylamino group. In general it is of advantage to couple the tetrazo compounds on both sides with the identical aminohydroxynaphthalenesulfonic acid.

Particularly valuable dyes are obtained by coupling a tetrazo compound with a 1-acylamino-8-hydroxynaphthalene-3:6- or -4:6-disulfonic acid (acyl-H acid or acyl-K acid) which correspond to the formula H035 Z are particularly distinguished by the fact that they are I readily compatible with silver halide emulsions, more Z especially with optically sensitized silver halide emulsions,

in which one Z represents a hydrogen atom and the other that is to say that they have a relatively minor desensitiz- Z a sulfonic acid group. The acyl radical linked to the ing effect. amino group is preferably derived from a benzenesulfonic The dyes of the invention can be applied in a gelatine acid or a benzenecarboxylic acid. In this case the comsilver halide emulsion or together with a silver halide pounds to be used as coupling components correspond to emulsion in another colloid; they can also be incorporated the formula in droplets of a high-boiling crystalloid material or in a (7) HO special colloid layer superimposed upon the silver halide layer; they may be non-diffusing as such or they may have been renedered non-diffusing by suitable additives.

However, as is desirable for certain dye transfer processes,

Hogs they may be capable of dilfusion. The dyes of the invention can be cast in single layers or in multi-layer ma- Z terials or in multi-pack emulsions. They are suitable for producing records to be viewed by transmitted or incident light.

In conclusion it may be stated that the dyes are also suitable for other than photographic purposes. They can be used for dyeing a wide variety of materials, for example fibers of vegetable, animal, or synthetic origin, such as cotton, wool, silk or polyamidic fibers.

Unless otherwise indicated, parts and percentages in the following examples are by weight.

Example 1 183 parts of the diamine of the formula (10) H30 Ha C 3 H2N J- -NH2 ((L H2) r( 11 It is very readily soluble in water, does not diffuse in gelatine, has a high brilliance, it is readily compatible with silver halide emulsions, and can be bleached pure white.

The diamine of the Formula 10 used as starting material can be prepared as follows:

A solution of 128 parts of 1-amino-2-methylbenzene in 120 parts by volume of hydrochloric acid of 30% strength is treated with 54 parts of methyll-n-nonylketone, and the temperature is raised within 4 hours with stirring from 60 to 110 C. The Whole is then distilled While raising the temperature to 140 C., whereupon an aqueous layer and an oily layer separate in the receiver. The oil is isolated and returned to the reaction vessel. The

solidified mixture is then heated under reflux for about 8 hours at 140 C., taken up in water, rendered strongly alkaline with sodium hydroxide solution, and the separated oil is subjected to steam distillation to recover the excess l amino-Z-methylbenzene. The oily residue remaining in the distillation vessel is dissolved in benzene, dried over calcium chloride, freed from benzene and stirred with acetic anhydride. When the mixture is left to itself, the acetyl compound crystallizes out; after having been recrystallized from acetone it melts at 170 C.

A mixture of 225 parts of the acetyl compound, 2000 parts by volume of aqueous ethanol of 50% strength and 50 0 parts by volume of hydrochloric acid of 30% strength is refluxed for 8 hours, whereupon the alcohol is distilled off. The solution contains the hydrochloride of the di- 1 Cl-SO2I| IH OH amine of the Formula 10 and can be used as it is for the preparation of the tetrazo compound. The diamine itself can be isolated from this solution with sodium hydroxide; on recrystallization from petroleum other it forms colorless crystals melting at 55 C.

H H39 I H3 l (CH2) sC s C a (1 Ha i I I 6 Example 2 The following disazo dyes are prepared v8.5 described in Example 1 by coupling on both sides the tetrazo compounds of the undermentio-ned diamines with 1-(3-acetylamino benzoylamino) 8-hydroxynaphthalene-3:6-disu1- ionic acid. For this purpose there are used the diamines of the formula E (IDHE wherein R represents the following atomic groupings:

l-amino-Z-methylbonzene melting point condensed with acetyl compound, C.

n-amylmethylketone 207 n-hexylmethylketone 197 (c) n-heptylmethylketone 178 Example 3 18 parts of the 2:2-di (3-methyl-4'- aminophenyl)-nundecane of the Formula 10 or the corresponding quantity of 2:2-di-(4-aminophenyl)-n-undecane are tetrazotized in an aqueous hydrochloric acid solution and coupled in a solution, allnalinized with sodium carbonate, With 52 parts of 1-(4-chloro-2:5'-dimethylphenyl-sulfonylamino) 8 hydroxynaphthalene-3:6-disulfonic acid. The dye formed is isolated, and purified by being dissolved in water and precipitated again with sodium chloride; it is obtained free from salt by being dissolved in water, precipitated with sodium acetate and washed out with ethanol. In the form of its free acid it corresponds to the formula (CH2)80H3 Ho3s S0311 It is readily soluble in water and is of a pure purple tint. When incorporated in a gelatine layer it does not diffuse into an adjacent layer and can be bleached in the presence of a silver image without forming undesirable colored decomposition products.

Example 4 violet impurities by repeated reprecipitation. It dyes gelatine a pure bluish green tint. As the yellow dye for the non-sensitized silver bromide emulsion there may be used, for example, the dye obtained in the following manner:

175 parts of l-aminobenzene-3-sulfonic acid are diazo- A cellulose acetate film is coated with the following layers in the undermentioned order of succession:

(1) A silver bromide emulsion sensitized to red which contains the cyan dyestufi? of the formula HOzS- SOzH Hogs -SO:;H

O-CHa (2) A silver bromide emulsion sensitized to green A n l s which csmtains the Purple dyestufi of the Formula 11 3351115151 331filfidl ihifie scnbed m above Example formed is salted out, filtered ott', dissolved in water and (3) A yelow i f formed collolqal treated at room temperature with phosgene while keep- (4) A non-sens1t12cd silver bromide emulsion contaming the reaction solution at a neutral reaction by adding mg a ycnow azo sodium carbonate. On completion of the phosgenation The film produced as descnbed above is Processed by the reaction mixture is allowed to turn acidic, the dye the usual methods of the silver dye bleach process. Its which has separated in brown flocks is filtered off and photosensitivity in all its dyed layers is sufficient for the thoroughly Washed with Water The residue is digested usual lighting conditions material is exposfidflfor with s dium carbonate solution of 2% strength, whereexample under, a colored posmve master daveloped a upon a small amount of dye present, which diffuses slightmetol hydroqmnone developer fixed and b h a ly in gelatine, passes into solution, whereas owing to the dye bleach bath. prepared from hydrochlonc salting-out effect of sodium carbonate the main product urea and Phenazme' After removal of the excess sllver m does not dissolve. The residue is dried; it forms a brown a Farmers reducer a record in natural colors is obtained. It is of advantage to subject the record after the last water igt gi i t figg 1S readlly Soluble In Water Wuh a pure bath and before drying, for 3 minutes to a treatment in a What is Claimed f P t sodium carbonate solution of 1% streng.h and th-n to a 1. A disazo dyestufl, of the formula in which -U is a member selected from the group consisting of CO and -SO at least two and at most five V s and at least two and at most five V s are H, 0 to two V s and O to two V s are ---CH 0 to one V and O to one V are Cl, 0 to one V and 0 to one V are CH CONH, and m and 11 each stands for a whole number, the sum (m+n) being at least 5.

2. A disazo dyestuff which corresponds to the formula The azo dye of the Formula 14 can be prepared as follows:

198 parts of l-amino-Z:5-dimethoXy-4-nitrobenzene are diazotized in a hydrochloric acid suspension and the diazo compound is coupled with 361 parts of l-acetylamino-S-hydroxynaphthalene 3 :6 disulfonic acid. The resulting nitromonoazo dye is reduced in an alkaline me- V1 1 V2 V2 V1- 0 O-NII 011 113C OH: HO I-INOC -V:

1 l V1 V N=N T N: V2 V1 11038 SO3H (CH2) DCH3 HOgS SO3H dium with sodium sulfide to form the aminomonoazo dye in which 2 to 5 V s and 2 to 5 V s represent hydrogen which is purified by reprecipitation, then diazotized, and atoms, 0 to 2 V s and O to 2 V s methyl groups, 0 to 1 the diazo compound is coupled in a mixture of pyridine V and 0 to 1 V represent a chlorine atom, O to 1 V and aqueous ammonia with 542 parts of 1-(4-benzoyl- 5 and 0 to 1 V an acetylamino group, and p stands for a amino-benzoylamino) 8 hydroxynaphthalene-3:6-diwhole number of at least 5 and at the most 8. sulfonic acid, The resulting disazo dye is freed from 3. The disazo dyestuff of the formula J13C-CO-NH NH-COCH3 GOO-EN on me cm HNOC l l (3H3 I 11038 SO3H (CH2)BCH3 HOaS- SOaH 3,1 1 9,8 1 1 0 4. The disazo dyestul'f of the formula H 0 CH3 5. The disazo dysstuff of the formula 1130-00-1: r m 0o 0 H3 O0 OHN 0 H H30 CH3 HO HNO 0 l: --N=N IIO3S- SO3H (CH2) 4CH3 H035 -SO:4H

6. The disazo dyestuff of the formula H3O COITI]EI I\|IHC0 0 H3 0 OI'IN 011 H3O CH3 1-10 LI -0 0 noas- SOaH (0 2) 50 H3 H03s- -s on 7. The disazo dyestulf of the formula H30 00-1 IH 1 11000 0 II:

I O-o O-HN OH H3O CH3 HO HN-Oc-O l I I s I References Cited in the file of this patent UNITED STATES PATENTS 1,856,217 Kalischcher et al May 3, 1932 2,286,837 Seymour et a1. June 16, 1942 FOREIGN PATENTS 89,557 Switzerland June 1, 1921 

1. A DISAZO DYESTUF OF THE FORMULA 